Topic: Enzymes Aim: Why are enzymes important to living things?

What are enzymes? A protein catalyst Made of proteins What do enzymes do? Changes the rate of a chemical reaction. They speed up metabolic reactions in cells

Enzymes are made of proteins Each enzyme is specific to a reaction each enzyme needs to be the right shape for the job Oh, I get it! They are made proteins

How are enzymes named? enzymes are named for the reaction they help/after their substrate. lactase break down lactose sucrase breaks down sucrose proteases breakdown proteins lipases breakdown lipids DNA polymerase builds DNA Oh, I get it! They end in -ase

What determines the function of an enzyme? The shape of the enzyme Lock & Key model shape of protein allows enzyme & substrate to fit specific enzyme for each specific reaction

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Why are enzymes important to living things Why are enzymes important to living things? Nothing works without enzymes! all chemical reactions in living organisms require enzymes to work building molecules synthesis enzymes breaking down molecules digestive enzymes enzymes speed up reactions “catalysts” enzyme + We can’t live without enzymes! enzyme +

2 Types of Chemical Reactions controlled by Enzymes Synthesis Reaction building molecules B. Digestion Reaction breaking down molecules + +

Examples Synthesis reaction Digestion reaction enzyme enzyme + + Making larger molecules from smaller molecules enzyme + Digestion reaction Breaking larger molecules into smaller molecules enzyme +

Do enzymes get used up after they completed their jobs Do enzymes get used up after they completed their jobs? No,enzymes aren’t used up Enzymes are not changed by the reaction used only temporarily re-used again for the same reaction with other molecules very little enzyme needed to help in many reactions substrate product active site enzyme

Enzyme vocabulary Enzyme Substrate Products Active site Biological catalyst that speeds up specific a chemical reaction Substrate molecule that enzymes work on Products what the enzyme helps produce from the reaction Active site part of enzyme that substrate molecule fits into

What factors affect enzyme action? 1. Temperature why? enzyme has to be right shape 2. pH (acids & bases)

Factors Affecting Enzyme Activity: 1. Temperature Effect on rates of enzyme activity Optimum temperature The temperature at which enzyme works best. human enzymes 35°- 40°C (body temp = 37°C) Raise temperature (boiling) denature protein = unfold = lose shape Lower temperature T° molecules move slower fewer collisions between enzyme & substrate

Temperature 37° Optimum temperature human enzymes What’s happening here?! 37° Increasing the temperature denature (destroys) the shape of the protein. reaction rate Change shape = useless temperature

Effect of high temperature on enzyme activity Enzyme works based on their shape. Over heating denatures (destroys) the shape of the enzyme. Enzymes no longer work once the shape is changed.

Factors Affecting Enzyme Activity: 2. pH (how acidic something is) Effect on rates of enzyme activity changes in pH changes protein shape~ Denatures most human enzymes = pH 6-8 depends on where in body pepsin (stomach) = pH 3 trypsin (small intestines) = pH 8

pH 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Optimum pH for trypsin Optimum pH for pepsin stomach pepsin intestines trypsin What’s happening here?! reaction rate 1 2 3 4 5 6 7 8 9 10 11 12 13 14 pH

For enzymes… What matters? SHAPE! SHAPE! SHAPE!

You need to be able to read the pH scale in order to complete this worksheet. pH scale goes from 0-14. It is used to measure how acidic or basic something is.

How to read the pH scale pH lower than 7 indicates pH = 7 means Neutral (water) pH lower than 7 indicates Acidic solution pH greater than 7 indicates basic solution

Acidic Basic Acidic Neutral

Hint: Remember, less than 7 is acidic. Greater than 7 is basic